docs: def iter_chunks_class(self):
          """
          Yield each readable chunk present in the region.
          Chunks that can not be read for whatever reason are silently skipped.
          This function returns a :class:`nbt.chunk.Chunk` instance.
          """
          for m in self.get_metadata():
              try:
                  yield self.chunkclass(self.get_chunk(m.x, m.z))
              except RegionFileFormatError:
                  pass